Presently many methods and apparatuses are known for separating a desired isotope from one or more others. A presently used commercial process utilizes gaseous diffusion whereby the isotopes are separated by their mass differences. Another commercial process utilizes separation of the isotopes by centrifugal force.
Other promising approaches are the Dawson process, as exemplified by U.S. Pat. No. 4,059,761 to John M. Dawson. Here the isotopes are differentially energized in a dense plasma by stimulating them by a resonant frequency. Another promising approach is the one jointly carried out by Jersey Nuclear-Avco Isotopes, Inc. A representative patent for this approach is U.S. Pat. No. 3,772,519 to Levi, et al. Referring to the patent to Levi, reference is made to a paper entitled, "Laser Separation of Isotopes," by Richard N. Zare, in the Scientific American of February, 1977, pp. 86 through 98. Here a desired isotope is ionized by irradiating it with one or more lasers to remove an electron.
Reference is also made to the patent to Braunstein, Altshuler, and Frantz, U.S. Pat. No. 3,532,879. This patent discloses apparatus for deflecting atoms by a standing light wave. However, the neutral particle beam is directed against the electromagnetic standing wave at the Bragg angle. In this connection, reference may also be made to a patent by Altshuler, et al., U.S. Pat. No. 3,761,721. In this patent a beam of particles may be split into two beams by the process disclosed in the prior patent to Braunstein, et al.
The deflection of atoms by a resonant standing electromagnetic wave has been investigated in the recent scientific literature. Thus, a paper by Cook, et al., which appears in Physical Review A, Volume 18, No. 6, Dec. 1978, pages 2533 to 2537, is a theoretical study to prove mathematically that such a deflection of atoms is possible. Another paper, by Arimondo, et al., which appears in Physical Review Letters, Vol. 43, No. 11, Sept. 10, 1979, pages 753 through 757, relates to a laboratory experiment on a sodium beam to demonstrate the existence of a phenomenon, the phenomenon being that such a particle beam can be diffracted or scattered by a standing wave resonant to the internal excitation level of the atom.
It should be noted that neither of the two publications just referred to suggests the use of this phenomenon for the separation of isotopes; neither does any of the two papers propose that more than a single beam be used.
It is accordingly an object of the present invention to provide a method and apparatus for separating isotopes by generating a beam of particles and separating the desired isotope by scattering or diffracting the beam by a standing electromagnetic wave.